Adsorption device for compressed gas

ABSTRACT

An adsorption device for compressed gas or a non-compressed gas, is provided with a vessel with an inlet for the supply of a compressed gas or a non-compressed gas to be treated, and an outlet for treated gas and an adsorption element is affixed in the vessel. The adsorption element extends along the flow direction of the compressed gas or the non-compressed gas to be treated, between the inlet and the outlet. The adsorption element has a monolithic supporting structure that is at least partially provided with a coating that contains an adsorbent.

The present invention relates to an adsorption device for compressed gasor a non-compressed gas, for example compressed air or non-compressedair.

BACKGROUND OF THE INVENTION

More specifically, the invention concerns an adsorption device forcompressed gas or a non-compressed gas, whereby this adsorption devicecomprises a vessel in which an adsorbent, for example a drying agent, ora ‘desiccant’, is placed. The vessel concerned is provided with an inletfor supplying a compressed gas or a non-compressed gas to be treated,and an outlet for discharging treated gas.

The adsorbent concerned is generally realised in the form of aregeneratable adsorbent, or in other words an adsorbent that can beregenerated after reaching a certain degree of saturation. Forsimplicity, the following primarily refers to an adsorbent in the formof a drying agent, but the invention also extends to other adsorbents.For example, with a drying device it is indeed the case that as theadsorbent, that is constructed in the form of a drying agent, extractsmoisture from the gas to be dried, this drying agent will becomeincreasingly saturated with adsorbed moisture. Hence, it is usual, afterusing the drying agent for a certain time to dry compressed gas or anon-compressed gas, to regenerate this drying agent, for example byexposing it to a regeneration gas flow that extracts the moisture fromthe drying agent. Such a regeneration gas flow can consist of a fractionof the dried gas and/or hot gas for example whose relative humidity issufficiently low to be able to realise the regeneration of the dryingagent.

In some embodiments of drying devices for compressed gas or anon-compressed gas, use is made of two or more vessels of drying agent.With two vessels this principle of drying device is also referred to asa twin tower dryer. In such a type of drying device a compressed gas ora non-compressed gas, for example originating from a compressor, can bepassed through the first of the aforementioned vessels for example,where it will be dried by the drying agent in the vessel concerned,after having passed through an after cooler and a condensate separator(which may or may not form part of the after cooler concerned). Thisvessel consequently acts as a drying vessel.

At the same time, a regeneration gas flow can be guided through a secondaforementioned vessel in order to regenerate the drying agent in thatsecond vessel by extracting the moisture from this drying agent. Thiscan be done by making use of a gas that has already been dried, forexample, that is tapped off downstream from the drying vessel forexample and/or by supplying a gas flow that has been heated, for exampleby recovering the heat generated in the compressor during thecompression. In this last case it is called a “heat of compression” orHOC dryer. Other known regeneration principles can of course also beused.

When the drying agent in the drying vessel has reached a certain degreeof saturation, the gas flows through the first and the second vessel canbe changed over, such that the drying agent in the first vessel will nowbe regenerated by a regeneration gas flow while the second vessel willtake on the role of drying vessel. In this way the two or more vesselswill alternately operate as a drying pressure vessel and a regeneratingpressure vessel, such that continuity in the drying process can berealised. Examples of such drying devices with a number of vessels aredescribed for example in US 2003/023.941, U.S. Pat. Nos. 4,783,432,6,375,722, EP 1.776.171 and WO 2006/050.582.

The drying agent that is used in such adsorption devices with a numberof vessels often consists of grains of silica gel, activated alumina ora molecular sieve material, or a combination thereof. As is knownactivated alumina is produced by thermal dehydration or activation ofaluminium hydroxide Al(OH)₃, while molecular sieves consist of syntheticzeolites (crystalline aluminosilicates).

A limitation of such a type of drying device that comprises a dryingagent in a granular form, consists of the gas speeds through the vesselshaving to be limited in order to counteract grains moving against oneanother or even fluidisation. Indeed, due to the grains being set inmotion friction will occur between them, which in turn leads to dustformation and a reduced drying capacity. Other causes of such dustformation are for example pressure variations and/or thermal shocks.Moreover, the pressure drop across a twin tower dryer is relatively highand the desiccant grains have a rather high thermal mass.

Alternative drying devices are known for compressed gas or anon-compressed gas, whereby the drying agent is placed in a rotatingdrum, while a drying zone and regeneration zone extend in the vessel.During the operation of such a drying device, the drying drum will bemade to rotate by drive means provided to this end, such that the dryingagent in this drying drum will alternately be taken through the dryingzone and the regeneration zone. The compressed gas or non-compressed gasto be dried will be guided through the drying zone, while theregeneration gas flow is guided through the regeneration zone, in orderto realise simultaneous drying of compressed gas non-compressed gas inthe drying zone and regeneration of the drying agent in the regenerationzone.

Examples of such drying devices that are provided with a rotating dryingdrum are described for example in WO 00/033.943, WO 00/074.819, WO01/078.872, WO 01/087.463, WO 02/038.251, WO 2007/079533, WO2005/070.518, WO 2006/012.711, GB 1.226.348, GB 1.349.732, GB 1.426.292,U.S. Pat. Nos. 3,490,201, 5,385,603 and 8,349,054.

The drying agent or desiccant that is used in the known drying devicesfor drying compressed gas or non-compressed gas consists of silica gel,molecular sieves, activated alumina or a combination thereof, forexample. As is known, the drying agent can be affixed on a support suchas a corrugated structure of glass fibres or ceramic fibres that arerolled up for example to form a honeycomb structure in the vessel, forexample as described in U.S. Pat. No. 5,683,532.

In practice it turns out that with the known drying devices for dryingcompressed gas or non-compressed gas, under certain conditions such asin the event of insufficient regeneration of the drying agent andoversaturation thereof, the drying agent goes through a complexbreakdown process that in some cases can ultimately result in thefailure of the drying device, for example in the case of silica gel as adrying agent in a rotor, because the binder function of the silica geldecreases, which leads to a loss of structural strength of thesupporting glass fibre matrix, and also because the adsorbing functionof the silica gel decreases as a result of hydrolisation and breakdownof the silica gel structure.

Thus the adsorption behaviour and adsorption capacity of a silica gelrotor, in severe conditions of high moisture and high temperature willsubstantially change during the useful life of the rotor.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide an adsorption devicefor compressed gas or non-compressed gas that provides a solution forone or more of the disadvantages attached to the conventional, alreadyknown, adsorption devices that make use of an adsorbent.

To this end the invention concerns an adsorption device for compressedgas or non-compressed gas, whereby this adsorption device is providedwith a vessel with an inlet for the supply of a compressed gas or anon-compressed gas to be treated, and an outlet for treated gas andwhereby an adsorption element is affixed in the aforementioned vessel,whereby this adsorption element extends along the flow direction of thecompressed gas or the non-compressed gas to be treated between theaforementioned inlet and the aforementioned outlet, and, according tothe invention, consists of a monolithic supporting structure that is atleast partially provided with a coating that comprises an adsorbent.

An advantage of such an adsorption device according to the invention isthat there is no risk of movement or fluidisation, as no loose grains ofadsorbent are used. As a result dust formation is prevented, while arelatively high flow rate of the compressed gas or the non-compressedgas to be treated through the adsorption device is possible.

Moreover, such an adsorption device according to the invention enablesthe vessel to be placed vertically, sloping or even horizontally, whichis not possible with conventional drying devices that make use of agranular drying agent for example, as the horizontal use of such knowndrying devices can lead to a rearrangement of the grains and theformation of internal leakage paths and consequently a reduced dryerperformance.

According to a preferred characteristic of the invention, theaforementioned monolithic supporting structure comprises one or more ofthe following materials: ceramic material, metal foil, a fibre structureand a polymer. Particularly good results are obtained with the use of aceramic structure that contains cordierite.

Preferably the aforementioned adsorbent contains one or more of thefollowing materials: a zeolite, silica gel, activated alumina, activatedcarbon, metal organic frameworks, carbon molecular sieve (CMS), animpregnated adsorbent and a hybrid adsorbent. In particular ahydrophilic zeolite support is preferable. Good results are obtained bymaking use of faujasite or zeolite type X, in which thesilicon/aluminium ratio is between 2 and 3.

According to a particular embodiment of the invention, the adsorptiondevice comprises a number of adsorption elements placed in series in theaforementioned vessel along the flow direction of the gas.

The present invention also relates to an adsorption element for anadsorption device for compressed gas or non-compressed gas, whereby thisadsorption element comprises a monolithic supporting structure that isat least partially provided with a coating that contains an adsorbent.

In addition the invention also concerns a cartridge that comprises astack of adsorption elements that are provided with a monolithicsupporting structure that is at least partially provided with a coatingthat contains an adsorbent.

In addition the invention also concerns a cartridge that comprises asingle adsorption element that is provided with a monolithic supportingstructure which is at least partially provided with a coating thatcontains an adsorbent. This cartridge is interchangeable or replaceable.

BRIEF DESCRIPTION OF THE DRAWINGS

With the intention of better showing the characteristics of the presentinvention, a few preferred embodiments of an adsorption device accordingto the invention are described hereinafter by way of an example, withoutany limiting nature, with reference to the accompanying drawings,wherein:

FIG. 1 schematically shows an adsorption device according to theinvention;

FIG. 2 shows a cartridge of adsorption elements according to theinvention;

FIG. 3 shows the part indicated by F3 in FIG. 2 on a larger scale;

FIG. 4 shows a variant of an adsorption device according to FIG. 1 ;

FIG. 5 shows a variant of the invention in the mounted state of thestack of adsorption elements in a vessel; and

FIG. 6 shows a detail of the top edge of a stack of adsorption elementsin the mounted state in a vessel.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 schematically shows a possible embodiment of an adsorption device1 according to the invention, which in this case forms a drying deviceand which comprises two vessels 2A and 2B that are each provided with aninlet 3A and 3B respectively for the supply of a compressed gas to betreated (in this case dried) and an outlet 4A and 4B respectively forthe discharge of treated (in this case dried) compressed gas.

The respective outlets 4A and 4B are connected to a pressure pipe 5 of acompressor 6 via outlet pipes 5A and 5B, in this example an aircompressor. Each of the outlet pipes 5A and 5B can be shut off by meansof an outlet valve 7A and 7B respectively provided to this end.

Between the outlet valve 7A and 7B respectively on the one hand and theoutlet 4A and 4B respectively, a connection is provided on each outletpipe 5A and 5B to a discharge pipe 8A and 8B respectively that can beclosed off by means of a discharge valve 9A and 9B respectively, andwhich in this case, but not necessarily, is connected to a common outlet10.

The aforementioned inlets 3A and 3B are connected together by means of aconnecting pipe 11 in which a first set of two shutoff valves 12A and12B are placed in series. The valves 12A and 12B concerned are bypassedby a bypass pipe 13 in which a second set of two shutoff valves 14A and14B are placed in series.

The connecting pipe 11 and the bypass pipe 13 are connected together bymeans of a cooling pipe 15, in which a heat exchanger 16 and acondensate separator 17 are affixed. One end of the cooling pipe 15connects to the connecting pipe 11 between the first set of shutoffvalves 12A and 12B, while the other end of the cooling pipe 15 isconnected to the bypass pipe 13, between the second set of shutoffvalves 14A and 14B.

In this example each of the outlet valves 7A and 7B, the dischargevalves 9A and 9B and the shutoff valves 12A, 12B, 14A, 14B areconstructed in the form of a controllable shutoff valve that isconnected to a control unit 18, either via control cables provided tothis end, which for clarity are not included in the drawing, orwirelessly.

According to the invention, an adsorption element 19A and 19Brespectively is affixed in each of the aforementioned vessels 2A and 2B,in this case in the form of drying elements, more specifically in theflow path of the gas to be dried, or in other words according to theflow direction of the compressed gas to be treated between theaforementioned inlet 3A and 3B respectively on the one hand, and theaforementioned outlet 4A and 4B respectively on the other hand.

With regard to the first vessel 2A, an inlet side 20A of the adsorptionelement 19A will extend opposite the aforementioned inlet 3A, while anoutlet side 21A of the adsorption element 19A extends opposite theoutlet 4A.

Analogously the adsorption element 19B in the second vessel 2B has aninlet side 20B and an outlet side 21B that extend opposite the inlet 3Band the outlet 4B respectively.

According to the invention the adsorption elements 19A and 19B comprisea monolithic supporting structure that preferably, but not necessarily,consists of a ceramic structure that contains cordierite, for exampleCelcor© by Corning. Alternatively, according to the invention, othermaterials can also be used for the manufacture of the supportingstructure concerned, such as:

-   -   other ceramic materials such as mullite,        - or        -alumina or silicon carbide (SiC);    -   metal foil; or    -   a fibre structure, for example based on glass fibre, ceramic        fibre or other fibres, or a mixture of different types of        fibres; or    -   a polymer.

It goes without saying that the aforementioned list is not exhaustiveand the use of other materials is not excluded.

According to the invention, it is not excluded either that themonolithic supporting structure is made of a combination of two or moreof the aforementioned and/or other materials.

The material of the supporting structure preferably contains between 200and 1200 CPSI (cells per square inch), and more preferably between 350and 450 CPSI.

The wall thickness of the supporting structure is preferably between 2and 11 mil (milli-inch), and more preferably between 3 and 9 mil, andeven more preferably between 5 and 7.5 mil. In a most preferredembodiment, the wall thickness is between 6 and 7 mil, preferablyapproximately 6.5 mil.

The porosity of the wall of the supporting structure is preferablygreater than 5%, and more preferably greater than 10%, and even bettergreater than 20%.

The cells formed preferably have a square shape, but can present othershapes such as triangular, sinusoidal, circular, hexagonal and similar.

According to the invention the aforementioned monolithic supportingstructure is at least partially provided with a coating that contains anadsorbent.

According to the invention, the adsorbent concerned can contain one ormore of the following and/or other materials:

-   -   a zeolite, preferably a hydrophilic zeolite, but a hydrophobic        zeolite is also possible—this zeolite can be faujasite zeolite        type X for example, for example Zeolum F9 of Tosoh, or a mixture        of zeolite type X and A;    -   silica gel;    -   activated alumina;    -   activated carbon;    -   metal-organic frameworks;    -   carbon molecular sieve (CMS);    -   an impregnated adsorbent; and    -   a hybrid adsorbent.

The above list is not exhaustive and other materials are also possibleaccording to the invention.

The choice of the adsorbent depends on what treatment the gas to betreated must go through, such as drying or the removal of othermolecules such as oxygen or carbon dioxide, for example when using theadsorption device as a nitrogen generator, whereby the compressed gas tobe treated is compressed air.

The distribution of the particle size of the adsorbent is preferablysuch that D₅₀ is less than 10 μm and more preferably less than 4 μm.

In addition to the aforementioned adsorbent, the aforementioned coatingpreferably also contains a binder material, preferably an inorganicbinder material such as:

-   -   colloidal silica, for example Ludox-AS 40 of Grace Davison;    -   alumina; and/or    -   clay.

Moreover, if need be use can be made of an organic binder material suchas:

-   -   methyl cellulose;    -   polymers such as acrylic resins, vinyl resins and similar;        and/or    -   a material from the cellulose group.

In the example of FIG. 1 each vessel 2A and 2B contains one singleadsorption element 19A and 19B respectively, but the invention is notlimited as such, as, according to a variant of an adsorption device 1according to the invention, as shown in FIG. 2 , two or more adsorptionelements 19A or 19B can also be placed in series in a vessel 2A and/or2B along the flow direction of the gas.

In another embodiment, the compressor 6 is replaced by a blower orlow-pressure device.

FIG. 2 shows an example of a number of adsorption elements 19A stackedon one another, which in this example are disc shaped and all present aflat top and bottom surface.

In each case, a seal 22 is preferably provided between two adsorptionelements 19A stacked on one another, over the peripheral edge of theseadsorption elements 19A, in this case a ring-shaped seal that extendsbetween the interfaces of the stacked adsorption elements 19A with atleast one radial lip oriented inwards, and in this case with twoV-shaped radial lips 23 oriented inwards.

Preferably, shrink sleeving 24 is affixed over the peripheral wall ofthe entire stack of adsorption elements, that is preferably made of anelastic material that is not very permeable to gas, for examplepolyolefin. The shrink sleeving 24 concerned can also be affixed overjust a part of the height of the stack of adsorption elements.

The set of stacked adsorption elements 19A thus forms a cartridge thatis interchangeable or replaceable according to a particular aspect ofthe invention.

The operation of an adsorption device 1 according to the invention isvery simple and as follows.

In the first instance, in this example the first vessel 2A will fulfilthe role of a drying vessel, while the adsorption element 19B (that isthus a drying element here) will be regenerated in the second vessel 2B.

The compressor 6 draws in a gas, for example surrounding air, andcompresses this gas. The compressed hot gas is then carried through theoutlet pipe 5B via the pressure pipe 5 via the open outlet valve 7B tothe outlet 4B of the second vessel 2B.

The hot compressed gas will have a sufficiently low relative humidity toextract moisture from the adsorption element 19B present in the dryingagent and will thus regenerate this adsorption element 19B. In otherwords the desiccant is dried in the second vessel 2B.

The hot moist gas is then driven via the open shutoff valve 14B to thecooling pipe 15, where it is guided successively through the heatexchanger 16 and the condensate separator 17 to then be carried via theopen shutoff valve 12A and the connecting pipe 11 to the inlet 3A of thefirst vessel 2A.

The cold compressed gas that is 100% saturated will enter the firstvessel 2A via the inlet 3A and be guided through the adsorption element19A.

The adsorbent present on the supporting structure will extract moisturefrom the gas during the flow of the compressed gas through theadsorption element 19A. In this example the adsorbent will consequentlyfulfil the role of a drying agent or desiccant material.

The gas that leaves the adsorption element 19A, at the outlet side 21Athereof, will be drier than the gas that entered the vessel 2A via theinlet 3A.

The dried compressed gas then flows, via the outlet 4A, through theoutlet pipe 5A and the open discharge valve 9A to the discharge pipe 8Aand to the outlet 10 connected thereto, which can be connected to aconsumer of dried compressed gas.

After a certain cycle time, the operation of both vessels 2A and 2B canbe changed over and the second vessel 2B can take on the role of adrying vessel, while the desiccant in the first vessel 2A can beregenerated.

On account of the fact that the adsorption device 1 according to theinvention does not make use of a granular desiccant, the vessels 2A and2B can be placed in any position such as vertical, horizontal or anyother position.

As the adsorbent is attached to a supporting structure there is no riskof fluidisation, such as with a granular desiccant, and consequentlydust formation cannot occur, not even at high gas speeds through theadsorption element.

When use is made of a number of adsorption elements 19A placed on oneanother, as shown in FIG. 2 , the gas will flow sequentially through thesuccessive adsorption elements, either as gas to be dried or as aregeneration gas.

The presence of the aforementioned seals 22 between successiveadsorption elements 19A prevents leakages being able to occur betweenthe side wall of the stack of adsorption elements 19A on the one hand,and the inside wall of the vessel 2A on the other hand. For the rest,the same applies to the use of such a stack of a number of adsorptionelements 19B in the second vessel 2B, which of course is also possibleand can be provided with the said seals 22.

FIG. 4 shows another embodiment of an adsorption device 1 according tothe invention, whereby in this case there is only one vessel 25 in whichan adsorption element 19 is rotatably affixed. The adsorption element 19is attached to drive means, for example in the form of an electric motor26.

As with known rotary drum dryers a regeneration zone and an adsorptionzone (in this case a drying zone) extend in the vessel. The pressurepipe 5, in this case originating from a compressor 6, connects to theinlet of the regeneration zone, as is the case with known HOC dryers.The outlet of the regeneration zone is connected to the inlet of theadsorption zone in a known way via a connecting pipe 27. A heatexchanger 16 and condensate separator 17 are provided in the connectingpipe 27 concerned.

Finally, the outlet of the regeneration zone is connected to the outlet10 via a discharge pipe.

In another embodiment, the compressor 6 is replaced by a blower orlow-pressure device.

The operation of an adsorption device according to FIG. 4 is analogousto that of known HOC dryers with a rotary drum in which a drying agentis provided. However, on account of the structure of the adsorptionelement 19, such an improved adsorption device according to theinvention is not susceptible to failure on account of a reduction ofstrength. After all, the monolithic supporting structure of anadsorption element in an adsorption device of the invention does notlose structural strength, not even under severe conditions of highhumidity and high temperature.

The embodiments of an adsorption device 1 according to the inventionshown in the drawings are both full-flow HOC dryers, however theinvention is not limited as such, as an adsorption device 1 according tothe invention does not necessarily have to operate according to afull-flow principle. Likewise, according to the invention it is notrequired either that the heat of compression is employed for theregeneration of the adsorbent, but use can be made of any regenerationgas that originates from the process itself or otherwise, and which iscompressed gas or otherwise.

FIG. 5 shows a variant of the detail of claim 3, whereby in this casethe stack of adsorption elements 19A is affixed in the vessel 2A and apart of the wall of this vessel 2A can be seen.

In this example the seal 22 comprises a ring 28, for example but notnecessarily of aluminium, another metal or a polymer, whereby the insidediameter of this ring 28 is somewhat larger than the outside diameter ofthe adsorption elements 19A, which in this example are disc shaped.

The ring 28 extends over the peripheral edge of the ends of theadsorption elements 19A placed on one another. On its inside peripherythe ring 28 concerned is provided with a radial edge 29 orientedinwards, against which the ends concerned of the adsorption elements areaffixed.

In order to obtain a good seal and prevent leakage paths, a sealinglayer 30 and 31 respectively is affixed over the entire periphery oneither side of the edge 29 concerned, for example in the form of aquantity of adhesive or another sealing element.

In this example, the ring 28 is provided over its outer periphery withtwo practically parallel ribs 32 at an axial distance from one another,between which a seal 33 is affixed, in this case in the form of anO-ring. According to the invention the presence of the ribs 32 is notstrictly necessary. For example, only one rib can be provided on whichthe seal 33 rests, or can be mounted immovably on the ring 28 of theseal, or form an integral part of this.

When mounting the cartridge consisting of adsorption elements stacked onone another, as shown in FIG. 5 , the seal 33 will press against theinside wall of the vessel 2A. In this way, this construction not onlyensures that leaks between the adsorption elements 19A mutually, butalso between the cartridge and the wall of the vessel, are prevented.

Again it is clear that the embodiment concerned is not limited to anapplication in the vessel 2A, but it can just as well be applied in thevessel 2B of FIG. 1 and/or in the vessel 25 of FIG. 4 , or in any othertype of adsorption device 1 according to the invention.

FIG. 6 shows a detail of a top edge of a top part of a stack ofadsorption elements 19A in a mounted state in a vessel 2A. The wall ofthe vessel 2A is shown in the right of the drawing. The sameconstruction is possible on the bottom edge of a stack of adsorptionelements or, when use is made of only one adsorption element in avessel, on the top and/or bottom side of such a separate adsorptionelement.

A V-shaped seal 34 is pushed over the free peripheral edge of theadsorption element 19A, in other words the peripheral edge that is notoriented towards another adsorption element 19A, all such that a firstarm 35 of the seal presses against the axial top surface 36 of theadsorption element 19A, while the second arm 37 of this seal 34 pressesagainst the radial outside wall 38 of the adsorption element 19A.

In this case, the V-shaped seal 34 presents a lobate protuberance 39 onthe top, or in other words on the side where the two arms 35 and 38 areconnected together.

In an embodiment where a single cartridge with a single element isemployed, it is preferred that the V-shaped seal is pushed over both thetop peripheral edge and the bottom peripheral edge of the cartridge. Theterms top and bottom are applicable when the cartridge is configured asshown in FIG. 6 . However, the cartridge may be configured at any angle,not just as shown in FIG. 6 .

According to a preferred characteristic of the invention, pressing meansare provided that press a part of the seal 34 radially against theinside wall of the vessel 2A. In this example the pressing meansconcerned comprise a conical ring 40, that is pressed by means of aspring 41 against the lobate protuberance 39 of the seal 34. To this endthe conical surface of the conical ring 40 is oriented towards the seal34 concerned and presses the spring by its other end against the coverof the vessel 2A, for example.

It goes without saying that the part of the seal 34 that is pressedagainst the inside wall of the vessel 2A does not necessarily have to belobate, and this part can be constructed in many different ways.

The largest outside diameter of the conical ring 40 is preferably, butnot necessarily, almost as large as the inside diameter of the vessel2A.

Alternatively, in the construction as shown by way of an example in FIG.6 , the seal at the top and bottom of the cartridge, consisting of astack of adsorption elements 19A, can be obtained in different ways, forexample by making use of a glued ring and an O-ring similar to theprinciple shown in FIG. 5 .

Alternatively, the seal at the top and bottom of a single cartridge,consisting of a single adsorption element, can be obtained in differentways, for example by making use of a glued ring and an O-ring similar tothe principle shown in FIG. 5 .

Although in the above description an adsorption device in the form of adrying device for adsorbing moisture is primarily described, theinvention also relates to other types of adsorption devices such asnitrogen generators and similar, whose adsorption element is able toadsorb certain gas molecules such as oxygen, carbon dioxide and/orsimilar. By removing such gas molecules from compressed air for example,as is known, nitrogen can be generated.

The present invention is by no means limited to the embodimentsdescribed as an example and shown in the drawings, but an adsorptiondevice according to the invention for compressed gas can be realised inmany forms and dimensions, without departing from the scope of theinvention.

What is claimed is:
 1. An adsorption device for a gas, comprising avessel with an inlet for a gas to be treated, and an outlet for treatedgas, and an adsorption element affixed in the vessel, wherein theadsorption element extends along a flow direction of the gas to betreated, between the inlet and the outlet, wherein the adsorptionelement comprises a monolithic supporting structure that is at leastpartially provided with a coating that contains an adsorbent, andwherein at least one adsorption element is placed in the vessel alongthe flow direction of the gas, and wherein a V-shaped seal is over afree peripheral edge of the at least one adsorption element, such that afirst arm of the seal presses against a surface of the at least oneadsorption element, while a second arm of the seal presses against theoutside wall of the at least one adsorption element, and wherein saidgas is a compressed gas or a non-compressed gas.
 2. An adsorption devicefor a gas, comprising a vessel with an inlet for a supply of a gas to betreated, and an outlet for treated gas, and at least one adsorptionelement affixed in the vessel, wherein the at least one adsorptionelement extends along a flow direction of the gas to be treated, betweenthe inlet and the outlet, wherein the at least one adsorption elementcomprises a monolithic supporting structure that is at least partiallyprovided with a coating that contains an adsorbent, and wherein aV-shaped seal is over a free peripheral edge of the at least oneadsorption element, such that a first arm of the seal presses against asurface of the at least one adsorption element, while a second arm ofthe seal presses against an outside wall of the at least one adsorptionelement, and wherein said gas is a compressed gas or a non-compressedgas.
 3. An adsorption device for a gas, comprising a vessel with aninlet for the supply of a gas to be treated, and an outlet for treatedgas, and at least one adsorption element affixed in the vessel, whereinthe at least one adsorption element extends along a flow direction ofthe gas to be treated, between the inlet and the outlet, wherein the atleast one adsorption element comprises a monolithic supporting structurethat is at least partially provided with a coating that contains anadsorbent, and wherein a V-shaped seal is over a free peripheral edge ofthe at least one adsorption element, such that a first arm of the sealpresses against a surface of the at least one adsorption element, whilea second arm of the seal presses against an outside wall of the at leastone adsorption element, and wherein said gas is a compressed gas or anon-compressed gas.
 4. A cartridge comprising at least one adsorptionelement for an adsorption device for a gas, wherein the at least oneadsorption element comprises a monolithic supporting structure that isat least partially provided with a coating that contains an adsorbent,and wherein a V-shaped seal is over a free peripheral edge of the atleast one adsorption element, such that a first arm of the seal pressesagainst a surface of the at least one adsorption element, while a secondarm of the seal presses against an outside wall of the at least oneadsorption element, and wherein said gas is a compressed gas or anon-compressed gas.
 5. A system comprising: an adsorption deviceconnected to a compressor, a blower, or a low-pressure device, andconfigured to receive the a gas to be treated, said adsorption devicecomprising: a regeneration zone and an adsorption zone, wherein at leastan outlet of the regeneration zone is connected to an inlet of theadsorption zone, at least one vessel provided in the regeneration zoneand/or the adsorption zone, said at least one vessel comprising theinlet for the supply of the gas to be treated at a first end of the atleast one vessel, and the outlet for a treated gas at a second end ofthe at least one vessel, and at least one adsorption element affixed inthe at least one vessel, wherein the at least one adsorption elementextends along a flow direction of the gas to be treated, between theinlet at the first end and the outlet at the second end, wherein theadsorption element comprises a monolithic supporting structure that isat least partially provided with a coating that contains an adsorbent,and wherein a V-shaped seal is over a free peripheral edge of the atleast one adsorption element, such that a first arm of the seal pressesagainst a surface of the at least one adsorption element, while a secondarm of the seal presses against an outside wall of the at least oneadsorption element, and wherein said gas to be treated is a compressedgas or a non-compressed gas.
 6. The adsorption device of claim 1,wherein the monolithic supporting structure comprises at least one ofthe cordierite, mullite,

- or

-alumina or silicon carbide (SiC), a metal foil, glass fiber, ceramicfiber, or a polymer.
 7. The adsorption device of claim 1, wherein themonolithic supporting structure contains between 200 and 1200 CPSI(cells per square inch), has a wall thickness of between 2 and 11 mil(milli-inch), and has a wall porosity greater than 5%.
 8. The adsorptiondevice of claim 1, wherein the monolithic supporting structure containsbetween 350 and 450 CPSI (cells per square inch), has a wall thicknessof between 3 and 9 mil (milli-inch), and has a wall porosity greaterthan 10%.
 9. The adsorption device of claim 1, wherein the monolithicsupporting structure has a wall thickness of between 5 and 7.5 mil(milli-inch), and has a wall porosity greater than 20%.
 10. Theadsorption device of claim 1, wherein the adsorbent comprises one ormore of a zeolite, a silica gel, an activated alumina, an activatedcarbon, a metal-organic framework, a carbon molecular sieve (CMS), animpregnated adsorbent, and a hybrid adsorbent.
 11. The adsorption deviceof claim 1, wherein the distribution of the particle size of theadsorbent is preferably such that D₅₀ is less than 10 μm.
 12. Theadsorption device of claim 1, wherein the coating comprises a binderselected from colloidal silica, alumina, clay, methyl cellulose, anacrylic resin, and a vinyl resin.